This invention relates to an inline valve. More particularly, but not by way of limitation, this invention relates to a flow valve used in the drilling of wells, and a method of using the flow valve.
In the search for oil and gas, operators drill wells many thousands of feet into the earth. The target of the drilling programs are subterranean reservoirs that contain hydrocarbons in liquid and gaseous states. A rotary drill bit is used to bore the hole. Different types of drilling bottom hole assemblies are available. For instance, a traditional tri-cone bit may be attached to a drill string, and wherein the drill string is rotated from the surface in order to rotate the bit. Another bottom hole assembly includes a drill motor placed upstream of the bit, and wherein the drill string remains stationary, but the drill motor causes the bit to turn thereby boring the well.
Generally, a drilling fluid is circulated within the bore hole. The drilling fluid has several purposes including but not limited to lubricating the bit, preventing hole sloughing, and containing the in-situ reservoir pressure. In some instances, the reservoirs are over pressured. Ideally, an operator would utilize a heavier drilling fluid which has the effect of increasing the hydrostatic pressure of the drilling fluid column which in turn controls the reservoir pressure from migrating into the well bore. However, in some cases, the in-situ reservoir pressure migrates out into the well bore in an event known as a kick. These kicks can be very dangerous since they can lead to blow outs. As readily understood by those of ordinary skill in the art, the migration of reservoir fluids, and in particular natural gas, causes the hydrostatic drilling fluid column to decrease in pressure, which in turn can lead to the blowout.
Numerous devices have been used to prevent blowouts. All these devices suffer from certain deficiencies in today's drilling environment. There is a need for a valve that controls flow of a medium from an oil and gas well. There is a need for a flow valve that can be used in conjunction with a drill string, with the flow valve being placed close to the bit. There is also a need for a device that will prevent and/or control the migration of the pressure into the drill string's inner diameter. There is also a need for a device that will prevent premature breakage of the valve spring during usage. In another embodiment, there is a need for a flow valve that can control the flow at the surface of a drilling rig. These and many other needs will be met by the invention herein disclosed.